package org.apache.commons.graph.algorithms.visit

import org.apache.commons.graph.model.BaseLabeledEdge
import org.apache.commons.graph.model.BaseLabeledVertex
import org.apache.commons.graph.model.UndirectedMutableGraph
import java.util.*

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

class NodeSequenceVisitor : BaseGraphVisitHandler<BaseLabeledVertex, BaseLabeledEdge, UndirectedMutableGraph<BaseLabeledVertex, BaseLabeledEdge>, List<BaseLabeledVertex>>() {
    private val vertices: MutableList<BaseLabeledVertex> = ArrayList()

    /**
     * {@inheritDoc}
     */
    override fun discoverVertex(vertex: BaseLabeledVertex): VisitState {
        vertices.add(vertex)
        return VisitState.CONTINUE
    }

    /**
     * {@inheritDoc}
     */
    override fun onCompleted(): List<BaseLabeledVertex> {
        return Collections.unmodifiableList(vertices)
    }
}
